​Consider oxygen gas at standard temperature and pressure (STP). What is the approximate weight (in grams) of one mole of oxygen molecules at STP?

Correct option is D

The correct answer is: (d) 32

Explanation:
• One mole of oxygen gas (O₂) contains two oxygen atoms.
• Atomic mass of one oxygen atom = 16 u, therefore O₂ = 16 × 2 = 32 g/mol.
• Hence, the molar mass of oxygen gas at STP is 32 grams.

Information Booster:
• One mole of any gas at STP occupies 22.4 L.
• O₂ is a diatomic molecule, not monoatomic.
• Molar mass helps in converting moles to mass in chemical problems.
• STP (Standard Temperature & Pressure) = 0°C and 1 atm.